craftgrrl | hi all... sewing spandex?

Hi all, I just joined. I looked through the memories, and I didn't find any posts about sewing spandex. I'm probably being stupid, but I looked up the settings for knits in my necchi handbook and i think it had the tension at 2 or something.

however, when i try to sew spandex it either 1) gets sucked into the bobbin area, 2) makes stiches but they're all loopy and loose because the threading through the machine gets all loose (or really tight)

my machine does have a stretchy stitch, but that just cameout knotted immediately. same with zig zag. the straight stitch is the one that gets all loopy...

please help!